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View Full Version : Another loose scape mount, need help.



toolz568
06-12-2014, 06:42 PM
My bushmaster 450 is really hard on scope rings. Twice now I found the scope loose. It kills aluminum, so I am switching to steel. Anyone know of a set of great steel scope rings. My first thought is Berrett, but that might be overkill.

country gent
06-12-2014, 09:03 PM
Keep in mind if the rings dont give if the upper is aluminum the the uppers rail may be whats gives next.

toolz568
06-12-2014, 09:18 PM
Considering it is a flat top that would be bad. I don't shot hot loads so I am not sure why I should be having trouble. The first set was cheap, but the second set was not. Unless the second set was partially stripped when I installed it. Still want to try steel.

country gent
06-12-2014, 10:38 PM
Check to make sure you have the correct buffer and spring in the rifle. A friend bought a new one and it wouldnt function with anything ammo wise. seemed smooth and right working action by hand. We took it to Cam[p Perry on our yearly trip to comercial row and bushmasters armmorer looked it over and found the wrong buffer was installed. A to light spring or buffer will allow the carrier to slam with to mush force.

obssd1958
06-13-2014, 08:54 AM
My vote is for the Burris Zee Signature rings/mounts. The insert used in these rings not only keeps the scope from moving or getting loose, but they protect your expensive scope from getting scratched and gouged by rings that get tightened too much (or are out of alignment).
They are a little more spendy than standard rings, but they are all I'll buy.
Go here, to read about them:

http://www.burrisoptics.com/sigrings.html


Hope this helps...

Love Life
06-13-2014, 12:57 PM
Badger Ordnance.

Smoke4320
06-13-2014, 04:59 PM
second the NO steel rings on a AR15 flattop upper .. on heavy hitting calibers like 450 and 458 socom you need to look for rings with wide bases ..IE the more surface area touching the upper rail the better.. look at 6 screw rings (6 screws holding ring halves together )
a large crossbolt nut will also help in the tightening area

Screwbolts
06-14-2014, 11:20 AM
Gentlemen, and I do use the term very lousily including for myself. Both of my 50 BMGs are AR uppers of the, DJs Habitual Tinkering design. Hence "Screwbolts" .

Now I know "Thunder" weighs 29 pounds and the "Montana" is 36 pounds. They both use DPMS smooth sided heavy uppers.

36" barreled Montana ( Montana rifle co barrel) uses a High rise upper that has vents, 20x Super Sniper Scope, (heavy) in Leapold HD steel rings. I and my friends have poped over 2700 primers in its chamber. No scope or mount fail/loosening. Tank type muzzle brake. IMHO, big brakes are very hard on mounts and scopes.

Thunder was built using 24" of M2 barrel re-threaded and chambered, mil-spec chamber. DPMS smoothy again but not high. Has 1/2", slide on riser that utilizes set screws to lock in place, threaded straight down from top. Wears a Bushnell 10x40 3200 mildot scope in a set of heaving steel mounts same as other rifle. I cut the riser with a band saw from the front 90% to the back, then removed enough material to taper the cut to build in 39 minute of elevation in the riser when grove is clamped together. I then drilled from inside the upper to the top of the riser and theaded the Top of the cut piece to 10-32 then installed on upper using 3, 10-32 socket head bolts up threw the charge handle race way. This securely holds things together. This upped has been fired over 3400 times, no failer of any kind, scope or mounts. I origonaly used a Madi-Griffen muzzle brake on this rifle but at 1800 rounds +- it was eroded to the point that the scope was starting to come back and say hello every time the trigger was pulled. Scope was not moving in mounts, recoil was, lets say "Noticeable" . This upper now carries a home made Tank Brake and is a pleasure again to shoot.

I do understand that a Light rifle will have different recoil properties, but these uppers launch heavy projectiles after consuming, depending on powder something in the neighborhood of 225 gr of surplus mil-spec powder.

The mount I used have 2 torque screws on each that pinch the rail threw a steel keeper.

I have one RRA lower dedicated to these 2 uppers. it carries fire control parts only with a second hammer spring , A1 buffer tube and stock extended with a 3/4" spacer and a Morgin adjustable butt pad.

Ken

Junior1942
06-14-2014, 03:59 PM
Check for tolerance stack on your mount screws, i.e., a too long screw in a too shallow hole.

toolz568
06-15-2014, 09:28 PM
Thanks for the advice. I'm not sure how to check if I have the correct buffer tube and spring. I did switch to a endine hydraulic buffer and found a set of badger ordinance rings. Time to take it back to the range and kill paper.

thanks again for the advice.

nhrifle
06-15-2014, 10:19 PM
Another source might be airgun scope mounts. Magnum break barrel air rifles are known scope killers. Take a look at scopes and mounts recommended for the RWS models 48 and 54 as they are known to eat glass and rings not up to the task.